Automatic flood control device for internal combustion engine fuel systems



Oct. 6, 1959 ,c. PATTON 2,907,350

AUTOMATIC FLOOD CONTROL DEVICE FOR INTERNAL COMBUSTION ENGINE FUEL SYSTEMS Flled Oct 19. 1956 nvenkvr Cu'nfon Pa/fwv y vb! PATENT AMP/{5.7.5

United States Patent AUTOMATIC FLOOD CONTROL DEVICE FOR IN- TERNAL COMBUSTION ENGINE FUEL SYSTEMS Clinton Patton, Calgary, Alberta, Canada Application October 19, 1956, Serial No. 617,141

2 Claims. (Cl. 137780) My invention relates to new and useful improvements in flood control devices for internal combustion engines fuel systems and particularly such fuel systems including complex or multi-barrelled carburettors and diaphragm type fuel pumps.

Although this device is usable with any internal combustion engine utilizing a diaphragm type fuel pump, nevertheless, it is particularly adaptable for use with the present day engines which include multi-barrelled downdraught calburettors and relatively high pressure type diaphragm fuel pumps.

Following engine stoppage when the engine is hot, a re-starting problem arises from the residual fuel pump pressure which continues to exert fuel pressure on the carburettor needle valve and seat until the fuel pump diaphragm and spring become exhausted.

Under the majority of conditions this diaphragm and spring exhausts by forcing fuel past the needle valve and seat which causes a rise of fuel within the carburettor float chamber above the float chamber level. Inasmuch as conventional carburettors operate on the U-tube princi ple, any excess fuel passing into the float chamber, automatically passes into the barrels of the down-draught carburettors and then into the intake manifold resulting in a fuel-air mixture much richer than the engine would be capable of burning, particularly when said engine is hot.

The principal object then of this automatic flood control device is to cause complete and immediate elimination of residual fuel pump diaphragm pressure following the stopping of the engine, but in so doing not altering in any way the normal flow of fuel from the fuel pump to the calburettor inasmuch as no fuel is released from the system nor is the immediate supply of fuel necessary for re-starting the modern engine hampered in any way.

Inasmuch as the device has a by-pass connection to the fuel line, the main supply of fuel does not pass through this device so does not restrict normal flow, neither do particles of dirt or other foreign matter affect the efficiency of the device.

Furthermole, the device which is relatively small and compact can be positioned or located anywhere within the fuel line between the fuel pump and the carburettor and does not need any further support means upon the engine.

A further object of my invention is to provide a device of the character herewithin described which is operated by the engine manifold vacuum rather than by the fuel pump pressure and does not depend on gravity or seepage of a valve to overcome this residual fuel pump pressure.

With the foregoing objects in view, and such other objects and advantages as will become apparent to those skilled in the art to which this invention relates as this specification proceeds, my invention consists essentially in the arrangement and construction of parts all as hereinafter more particularly described, reference being had to the accompanying drawings in which:

Figure 1 is a side elevation of my device shown in situ.

Figure 2 is a view similar to Figure 1, but with my device shown in section.

In the drawings like characters of reference indicate corresponding parts in the different figures. I

Proceeding therefore to describe my invention in detail, reference should be made to the accompanying drawings in which I have illustrated a fuel line 1, it being understood that the end 2 is connected to the conventional diaphragm type fuel pump and the end 3 extendstowards the carburettor float chamber of the engine (not illustrated). v

My device is connected within this fuel line preferably by means of a T-junction 4, the stem 5 whereof is connected via a conduit 6 to my device collectively designated 7.

My device consists primarily of a collapsible enclosure 8 manufactured preferably of synthetic rubber or similar materials, the conduit 6 extending through the wall of this enclosure and being sealed therein by'means of sealing ring 9 It will, therefore, be apparent that during the normal operation of the engine, this enclosure 6 is full of gasoline indicated by the reference character 10.

This enclosure is in turn contained within a hemispherical cover 11 and the aforementioned conduit 6 passes through this cover and is sealed thereto'by means of nut and washer 12.

The base 13 of the hemisphere is spanned by a flexible diaphragm 14 which seals off the area or volume 15 inasmuch as the base 16 of the hemisphere is crimped around theperimetrical edge 17 thereof thus not only' retaining the diaphragm, but also maintaining the enclosure 15 in an air-tight condition remote from atmospheric pressure. It will be noted that there is a vent 18 within the base 19 of the hemisphere connected to atmosphere, so that atmospheric pressure can act upon the diaphragm as indicated by the arrow 20.

Means are provided to vary the effective volume of the enclosure 8 and takes the form of a conduit 21 extending through the wall of the hemisphere 11 to the volume or region 15, said conduit being connected to the inlet manifold by means of further conduit 22, it being understood that when the engine is operating an area of low pressure is present within the inlet manifold, which area of low pressure is, of course, communicated to the area 15 within the cover 11 of the hemisphere. also be noted that a rigid plate 23 is secured concentrically upon the diaphragm 14 and that the base 24 of the enclosure 8 rests upon this rigid plate.

In operation, when the engine is running, the area of low pressure created within the inlet manifold is communicated to the area 15 within the cover, thus partially exhausting same so that atmospheric pressure acts upon the diaphragm 14 which moves upwardly as illustrated in phantom in Figure 2. This distorts or compresses the resilient or flexible container 8 thus reducing its effective volume and this reduction in volume is maintained while the engine is operating.

As soon as the engine is stopped, the area of low pressure within the manifold is eliminated inasmuch as it returns to atmospheric pressure and consequently the diaphragm 14 returns to the original position shown in Figure 2 taking with it the flexible container 8, the base 24 of which is of course secured to the base 23. This increases the effective volume of the enclosure'which draws into itself excess fuel within the fuel line 1 thus enabling the fuel pump diaphragm and spring to exhaust. It will of course be appreciated that the change in volume of the enclosure 8 is designed to equal exactly the amount of fuel contained in one stroke of the fuel pipe diaphragm. This occurrence immediately relieves the pressure within the fuel line and thus prevents any flood- It will ing occurring in the engine, past the needle valve in the carburettor float chamber.

When the engine is re-started, the inlet manifold vacuum immediately draws up the diaphragm thus exhausting this excess fuel from the enclosure 8 into the fuel line and actually assisting in fillihg the carburettor float chamber in case this has become depleted due to evaporation. V

Since various modifications can be made in my invention as hereinabove described, and many apparently widely different embodiments of same made within the spirit and scope of the claims without departing from such spirit and scope, it is intended that all matter contained iii the accompanying specification shall be interpreted as illustrative only and not in a limiting sense.

What I claim as my invention isz 1. A fluid pressure accumulator for fuel systems of internal combustion engines, said accumulator comprising in combination a substantially hemi-spherical housing including a dome-shaped cover and a dished bottom wall having adjoining marginal edges secured together, anbrmally fiat stretchable diaphragm disposed transversely in the bottom portion of said housing in upwardly spaced relation from said bottom wall and having its marginal edge portion secured between the adjoining marginal edges of said bottom wall and cover, said diaphragm separating the interior of the housing into a relatively large and dome-shaped upper chamber and a relatively small and dish-shaped lower chamber, said bottomwall being provided with: a vent opening communicating said" lower chamber with the atmosphere, a dome-shaped fluid receiving container of flexible material positioned in said upper chamber and occupying a volume therein smaller than the capacity of the upper chamber, said container having a bottom seated on said diaphragm and a dome-shaped upper wall normally spaced along a major portion of its extent from the interior of said cover whereby to provide in said upper chamber an annular space between the cover and the container separate from the interior of the latter, a fluid conduit extending inwardly through the top of said cover and of the upper wall of said container, said conduit securing said container to said cover and communicating with the interior of the container, and a vacuum line connected to the cover in communication with the space between the cover and the upper wall of said container, whereby upon exhausting of air from said space atmospheric pressure acting through said vent opening upon the underside of said diaphragm may cause the latter to be upwardly deflected and compress the upper Wall of said container against said cover to propor tionately decrease the capacity of the container.

2. The device as defined in claim 1 together with a pressure plate of rigid material positioned on said diaphragm and underlying the bottom of said container, said plate having its marginal edge spaced radially inwardly from the marginal edge of the diaphragm whereby to facilitate upward deflection of the latter but maintain the bottom of the container in a substantially flat form when the diaphragm is upwardly deflected.

References Cited in the file of this patent UNITED STATES PATENTS 

